Field of the Invention
The present invention concerns techniques for automatic magnetic resonance imaging in which a magnetic resonance overall image is composed of several magnetic resonance partial images. In particular, the invention concerns such techniques that allow for an automatic determination of various magnetic resonance scanning ranges respectively for which a magnetic resonance partial image is recorded.
Description of the Prior Art
In recent years, magnetic resonance (MR) tomography has been established as an important imaging modality for examining objects, especially in medical diagnostics. For this purpose, magnetic moments (spins) of nuclei are deflected from their rest position (which typically lies parallel to a basic magnetic field of several Tesla) by irradiating radio-frequency (RF) pulses, and the signal emitted during relaxation of the spins is used for imaging. A special application area of MR imaging is the reproduction of large body regions, even up to the entire body, which are referred to as multi-station or whole-body MR imaging).
Typically, imaging region within an MR system has only limited dimensions that may be smaller than the body region to be imaged. Therefore, it is often required to compose an MR overall image from several MR partial images. For this purpose, the patient can be positioned at different positions within the MR system by a moveable and positionable bed or table. In this way, different regions of the patient come to be in the imaging volume of the MR system and thus the different partial images of the different regions can be recorded. Then it is possible to compose the MR overall image from the MR partial images. Typically, the imaging volume is defined by operational parameters of the MR system that are constant within tolerance ranges. Typically, the imaging volume is centered at an isocenter of the MR system, close to the geometric center of the basic field magnet.
However, present-day methods for multi-station MR imaging entail a number of limitations. For example, it can be required that the medical personnel have to implement many manual and complicated steps for planning the various positions of the patient from whom the MR partial images are being recorded. This can be very time-consuming and expensive. It is also not possible to preclude errors in the planning process, which could possibly limit subsequent medical diagnostics.
Therefore, there is a need for improved methods and systems for multi-station MR imaging. In particular, there is a need for methods and systems that allow for automated and simple multi-station MR imaging.